Bone Mineral Density Response With Denosumab in Combination With Standard or High-Dose Teriparatide: The DATA-HD RCT

Efficacy of Antiosteoporotic Medications in Patients With Rebound-Associated Fractures After Denosumab Discontinuation

Denosumab discontinuation results in rapid bone loss and increased risk of multiple rebound-associated vertebral fractures (RAVFs). The optimal treatment for patients who have sustained such fractures is currently unknown. We aimed to investigate the bone mineral density (BMD) changes achieved with various regimens in postmenopausal women who had sustained RAVFs after denosumab discontinuation in everyday clinical practice. In this multicenter, retrospective observational study, 39 Greek postmenopausal women from six regional bone centers throughout Greece with RAVFs after denosumab discontinuation were included. We collected BMD and fracture data before and 1 year after treatment with denosumab (n = 20), teriparatide (n = 8), zoledronate (n = 8) or teriparatide/denosumab combination (n = 3). Both lumbar spine (LS)-- and femoral neck (FN)-BMD were preserved with all regimens used. With the exception of zoledronate, a trend towards increase was observed with all regimens in LS-BMD. Three patients sustained additional fractures despite treatment reinstitution (2 with zoledronate and 1 with teriparatide). Among patients with RAVFs following denosumab discontinuation both antiresorptive (zoledronate and denosumab) and anabolic (teriparatide) treatment as well as the combination of denosumab with teriparatide seem to be effective in terms of BMD response.

Recent developments towards closing the gap in osteoporosis management

Background

A fracture that occurs in people with low bone mass in the setting of minimal trauma—such as a fall from standing height—meets the criteria for the clinical diagnosis of osteoporosis and qualifies this particular individual for being at high risk of further fractures, particularly in the first 2 years after the index fracture. Therefore, it is vital to identify those individuals at very high and high fracture risk with the potential of instantly starting osteoporosis therapy.

Main body

Currently, there are unmet needs in the management of bone fragility and fracture prevention. Therefore, re-stratification of the people according to their risk of fracture, and, also, identify what is and is not achievable using different osteoporosis therapies, represent a major step forward. In 2020, the dichotomisation of high risk into high and very high-risk categories, which represent a new concept in osteoporosis assessment, was published by the IOF and the ESCEO. This coincided with proliferation of the available therapies with different modes of action and new therapeutic targets for treating osteoporosis. Fear of complications, even though rare, associated with long-term bisphosphonates and the positive impact of osteoanabolic agents on fracture reduction and bone quality, have changed the prescribing patterns and paved the way for sequential and combined therapy.

Conclusion

The incorporation of recent concepts in osteoporosis and the development of new interventional thresholds have positive implication on strategies for osteoporotic patients’ diagnosis and management.

Combination Therapy of PTH and Antiresorptive Drugs on Osteoporosis: A Review of Treatment Alternatives

Antiresorptive drugs have been widely used for osteoporosis. Intermittent parathyroid hormone (PTH), an anabolic agent, increases osteoblast production rate and inhibits apoptosis of osteoblasts, thus increasing skeletal mass besides improving bone microarchitecture and strength. Combination therapy for osteoporosis produced great interests and controversies. Therefore, we performed a systematic literature search from PubMed, EMBASE, Scopus, Web of Science, CINDHL, and the Cochrane Database of Systematic Reviews using the search terms PTH or teriparatide combined with bisphosphonate, alendronate, ibandronate, risedronate, raloxifene, denosumab, and zoledronic acid with the limit osteoporosis. At last, 36 related articles were included for further analysis. Findings from previous studies revealed that combination therapy in different conditions of naive or previous bisphosphonate treatment might have different outcomes. The use of combination therapy, however, may be an alternative option among osteoporotic patients with a history of bisphosphonate use. Combined teriparatide with denosumab appear to show the most substantial and clinically relevant skeletal benefits to osteoporotic patients. Additional research is necessary to define optimal methods of developing sequential and/or cyclical combinations of PTH and antiresorptive agents.

Effects of Combination Denosumab and High-Dose Teriparatide Administration on Bone Microarchitecture and Estimated Strength: The DATA-HD HR-pQCT Study

In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 μg) teriparatide increased spine and hip bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 μg). To assess the effects of these combinations on bone microarchitecture and estimated bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 μg (n = 39) or 40 μg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of bone density, microstructure, and estimated strength, with greater gains in total bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

Fracture risk and management of discontinuation of denosumab therapy: a systematic review and position statement by ECTS

CONTEXT

Denosumab discontinuation is characterized by an increase in bone turnover overriding pre-treatment status, a rapid bone loss in the majority and multiple vertebral fractures (VFx) in some patients.

METHODS

A working group of the European Calcified Tissue Society (ECTS) performed an updated systematic review of existing literature on changes of bone turnover, bone mineral density (BMD), and fracture risk after denosumab discontinuation and provided advice on management based on expert opinion.

RESULTS

Important risk factors for multiple VFx following denosumab cessation are prevalent VFx, longer duration off therapy, greater gain in hip BMD during therapy, and greater loss of hip BMD after therapy according to a retrospective analysis of the FREEDOM Extension Study. Case series indicate that prior bisphosphonate therapy mitigates the biochemical rebound phenomenon after denosumab discontinuation, but it is uncertain whether this attenuation prevents BMD loss and fractures. Current evidence indicates partial efficacy of subsequent antiresorptive treatment with results seemingly dependent on duration of denosumab treatment.

CONCLUSIONS

A careful assessment of indications to start denosumab treatment is advised, especially for younger patients. A case for long-term treatment with denosumab can be made for patients at high fracture risk already on denosumab treatment given the favorable efficacy and safety profile. In case of denosumab discontinuation, alternative antiresorptive treatment should be initiated 6 months after the final denosumab injection. Assessment of bone turnover markers may help define the optimal regimen, pending results of ongoing RCTs. Patients having sustained VFx should be offered prompt treatment to reduce high bone turnover.

Genomic Medicine: Lessons Learned From Monogenic and Complex Bone Disorders

Current genetic studies of monogenic and complex bone diseases have broadened our understanding of disease pathophysiology, highlighting the need for medical interventions and treatments tailored to the characteristics of patients. As genomic research progresses, novel insights into the molecular mechanisms are starting to provide support to clinical decision-making; now offering ample opportunities for disease screening, diagnosis, prognosis and treatment. Drug targets holding mechanisms with genetic support are more likely to be successful. Therefore, implementing genetic information to the drug development process and a molecular redefinition of skeletal disease can help overcoming current shortcomings in pharmaceutical research, including failed attempts and appalling costs. This review summarizes the achievements of genetic studies in the bone field and their application to clinical care, illustrating the imminent advent of the genomic medicine era.

Combination and sequential treatment in women with postmenopausal osteoporosis

Introduction: Since postmenopausal osteoporosis is a chronic, potentially disabling condition requiring long-term treatment, the physician is expected to decide the optimal treatment strategy, e.g. how to use the available osteoanabolic and antiresorptive agents, sequentially or in combination, in the most effective and safe way, based on personalized patient care.Areas covered: Herein, the authors outline clinical data regarding the efficacy and safety of various sequential treatment strategies. More specifically, they compare the efficacy of osteoanabolic agents when they precede or follow antiresorptive treatment, as well as the efficacy of antiresorptives following other antiresorptives. Finally, the authors quote and discuss available evidence regarding the efficacy and safety of the co-administration of osteoanabolics and antiresorptives in comparison with monotherapies.Expert opinion: Initiation with an osteoanabolic agent followed by an antiresorptive seems to be the optimal treatment sequence, at least in patients with severe osteoporosis. Osteoanabolic treatment following antiresorptives seems to lead in more modest responses in bone mineral density (BMD) and bone turnover markers. Combination therapy with teriparatide and denosumab or zoledronate has achieved higher BMD gains compared to each agent alone; however, due to the high cost, combination therapy is rarely compensated. On the contrary, the combination of teriparatide with alendronate results in smaller BMD increases than TPTD monotherapy.